I started to do experiment on making the rims to have more depth On Welly's 1/18 Porsche 911 RS
Original model untouched
This wheel is from my leftover parts
Switching rear and front wheel and adding the ring to the back wheel
cutting sections from outer part of the wheel to allow the tire sit out in order to have the ring added to the wheel
untouched side
swithched front and rear wheels with ring added to the rear wheel
A bit more trimming to make sure the wheels stay in right position and not to stick out from fenders
Final result